Nombrex type 27 signal generator

[Bushbaby]

I've have been endeavouring to work on this and it appears that it isn't working at all. The solder joints look very crappy like some one has tinkered with it before. I'm almost tempted to write it off as a project on this basis.
One thing that is puzzling me is the schematic shows a lot more components than the part list that accompanies it. Is there any reason for this?

Thanks

Rob